1. Field of the Invention
The present invention relates to image processing technology for reconstructing one frame of image data by using image data that has been divided into a plurality of blocks and transmitted.
2. Description of the Related Art
A conventional X-ray image diagnostic system for capturing the interior of a subject by irradiating the subject with X-rays is known. Such an X-ray image diagnostic system is normally comprised of an imaging apparatus including an X-ray sensor and an image processing apparatus that processes image data obtained by image capture, and the apparatuses are respectively disposed at a distance of several meters to several tens of meters from each other. Consequently, processing to transmit image data between the imaging apparatus and the image processing apparatus is necessary in the X-ray image diagnostic system.
On the other hand, in recent years, with X-ray sensors becoming capable of performing processing at higher resolution and using more gradations, the throughput of image data has been increasing significantly. Demand for increasing frame rates has also been increasing. In view of this, for example, Japanese Patent Laid-Open No. 05-244340 proposes a technique for reading out image data from an X-ray sensor in an imaging apparatus using a plurality of readout circuits so as to concurrently perform such processing for a plurality of lines.
However, if the plurality of lines of image data is concurrently read out, the pieces of image data read out by the readout circuits need to be respectively consolidated in predetermined block units, stored in a memory, rearranged into a predetermined order, and then transmitted. Accordingly, such a configuration has problems in that the memory capacity of the imaging apparatus needs to be increased and, furthermore, data transmission requires considerable time.
Meanwhile, in order to address such problems, it is effective to add, to image data, position information to the blocks obtained when the image data was captured and to transmit the image data thereafter. Accordingly, the image processing apparatus can perform processing based on the position information so that the aforementioned problems where the memory capacity of the imaging apparatus needs to be increased or data transmission requires considerable time can be avoided.
However, when transmitting data, the occurrence of transmission errors is generally inevitable, and when transmitting image data to which position information has been added, a position information transmission error may occur in addition to an image data transmission error.
As for such image data transmission errors, if an error in transmission of part of image data occurs in the image data transmitted in blocks, only that part of the image data will be missing; thus, it can be said that influence on image data to be reconstructed by the image processing apparatus is relatively small.
On the contrary, if an error in the transmission of position information added to block-level image data occurs, that image data will be missing at the block level, resulting in a great influence on image data to be reconstructed by the image processing apparatus. Accordingly, it can be said that it is necessary to apply a technique such as error correction codes or the like (see, for example, Japanese Patent Laid-Open No. 08-237652) for a position information transmission error. In general, Hamming code, Reed-Solomon Code, and the like are known as a technique for the error correction code that can be applied to address such a transmission error.
However, when using such error correction codes as described above, there is a problem in that error correction is difficult if errors concurrently occur in each instance of transmission of position information added to a plurality of blocks (if a burst error occurs). That is, it is difficult to realize reconstruction of appropriate image data.